The wizard behind the “World of Warcraft,” lead systems designer Greg “Ghostcrawler” Street, is treated like a rock star in the world of online gaming. After all, he made WoW the world’s most-subscribed multi-player online role-playing game in history.

And though it has steadily been losing players, 700,000 in the second quarter alone, it still reigns supreme with 7.7 million fans worldwide in July.

It’s definitely not game over, but there’s constant talk about the next expansion, the next tweak, the next big thing, more China elements — all closely guarded secrets.

So, when warlock Ghostcrawler showed up last week at ChinaJoy, he was mobbed and treated like a celebrity at the big digital entertainment expo. What hints might the former American marine biologist drop?

“World of Warcraft” has been played on China for eight years. The current “Oriental” expansion, “Mists of Pandaria,” features a new character class, the Monk, a race of panda-like characters on the new continent of Pandaria, and various Chinese and Eastern elements. It was launched a year ago.

“China is an enormous market for us and there are more and more potential players all the time as people get computers and get online,” Street told Shanghai Daily in an interview. “There are a lot of people in smaller cities who were not customers a few years ago but are quickly becoming potential customers. A lot of younger people are growing up all the time into our demographic.”

As for attracting Chinese players and adding more Chinese elements, Street expressed caution.

“Traditionally going after a particular region, trying to cater to them too much, doesn’t always work well. We wanted to do the panda in this expansion because all of us at Blizzard Entertainment were really excited about it. It was an opportunity to have a different type of environment with more Eastern influence than the traditional Western European stuff we had done.”

Street, who is in his forties, has been designing games since 1998. He joined Blizzard in 2008 as lead systems designer on WoW. Today he’s a major presence in the online gaming community, always out there, interacting with fans.

Earlier he worked on the “Age of Empire” series, another household world, with Ensemble Studios. At that time he went by the name of Deathshrimp, a reference to his marine biology days.

Although he had no games experience, apart from playing, he left marine research after he realized graduate students had more fun in the field, while he was stuck behind a computer.

Many WoW gamers regard him as a god, however, at ChinaJoy, Street was modest about his celebrity.

“We are in an interesting position because we are relatively famous among a very small population, so in the right environment, like ChinaJoy, a lot of people would know you. But out in the street it’s not that common,” he said.

“Players have this idea that you are a celebrity and so you try to embrace that a little. You are going to be excited for them because you don’t want to disappoint them. You sometimes get the rock star mentality of wanting to be a big present for players.”

Street talked to Shanghai Daily.

Q: Why did you change from marine science to gaming?

A: The graduate students are out having all the fun in the field and after I graduated, I figured if I’m gonna be in front of a computer, might as well be playing games. At the time, there wasn’t a career as a designer, just as a programmer or an artist. As I grew older the company started to realize the value of people who just did design, who came up with ideas and tried to implement features instead of actually doing the code work or art.

Q: What does a game designer do?

A: I compare it to being a movie director. You are not running the camera and you are not the actor but you have the vision and you can communicate it to everyone. So I work with the programers and marketing team. There is a lot of back and forth. The coordination and the vision are very important. It’s a very communications-heavy role.

Q: What the key to good design?

A: A lot of it is triage of ideas, focus on the ideas in the middle, not impossible ones and not bad ones. Making them better is the best use of time.

Q: Does a science background help?

A: The best thing was understanding data because we got a lot of data and then had to understand statistics and graphs. In our work now, it’s very helpful to be able to look at the numbers. Knowing different ways to break up the data and coming to a conclusion that helps you make decisions is the best thing I got out of science.

Q: Is WoW an art or a commodity?

A: It’s both. It’s very similar to fashion where at the end of the day you are making a product that you are trying to sell but at the same time you want it to be practical but also fun. It’s also supposed to be entertaining so you have to look at it as something the player wants to purchase and spend time with. It also has to be exciting. That causes us to not be too “safe” with our design but still keep the customer foremost in our mind.

Q: What makes so many characters so popular and enduring?

A: If you could spell it (the essence of popularity) out, then you must put it in the safe and take it out every time you need something like that to happen again. Somehow we are tapping into the taste of our players. It’s also the interaction; we really try to connect with them.

In initial design, those units (characters) had to have a very strong silhouette because they are very small on the screen and you need to identify quickly whether that’s your character or another. So artists focused a lot on silhouette, making very striking characters that really stand out.

Q: What about their personalities?

A: Another reason for popularity is that our characters are often larger than life. They are very exaggerated personalities and they often experience a lot of pain, giving their personalities and their stories a lot of depth. I think players end up caring about the characters individually not just because they look really cool but because they have an element of humanity in them.

Q: What are you doing these days?

A: Our hands are full with all our projects. We have “StarCraft II;” we have “Blizzard All-Stars;” we are working on “Diablo III” and “Hearthstone,” so I know there are a lot of fans.

For “StarCraft II,” we finished the second and are working on the third. For “Warcraft IV,” I don’t know. Maybe there’s a chance we will work on “Warcraft” after that. Maybe we will work on “StarCraft” together. Maybe they will get bored with strategy games and do something totally different.

Q: So you’re not giving up on this (Warcraft) game?

A: No. I think in the future at some point in time we will very likely come back to that, it’s just too popular a game. A lot of the lore of the storytelling and the characters created so much content that we were able to use it for 10 years. It would be best from a lazy designer’s perspective to do another chapter.